Echocardiography, a noninvasive method of cardiac imaging, provides tomographic images of the cardiac chambers, walls and valves. The analysis of these images has been largely qualitative. The development of a microprocessor light pen analysis system has enabled us to develop a quantitative echocardiographic approach to the evaluation of the cardiac chambers and their function. Our work to date has been directed at 1) developing single and biplane methods of measuring the volume of the left ventricle, 2) developing single and biplane methods of measuring the volume of the left atrium, 3) developing a biplane approach to measuring the mass of the left ventricle 4) detecting contraction abnormalities associated with segmental ischemia of the left ventricle, 5) detecting contraction sequence abnormalities associated with pre-excitation of the left ventricle and 6) developing a method of directly measuring velocity of circumferential fiber shortening of the left ventricle. The above projects have been completed and now in progress to apply these techniques as follows: A) Measurement of myocardial mass in patients with left ventricular hypertrophy arising in association with hypertension, aortic stenosis and hypertrophic cardiomyopathy before, during and after alleviating elevated afterload. B) Measurement of serial changes in LV mass following acute myocardial infarction. C) Detection of early systolic contraction abnormalities in reversible ischemia by determining ejection fraction in the first third of systole. D) Detecting subgroups of diabetic heart disease by correlating cardiac volume with diabetic classification.